Pressure controlled gas lift valve



Jan. 18, 1955 T. E. BRYAN PRESSURE CONTROLLED GAS LIFT VALVE Filed Feb.18 1950 I F R H 72101445 5 er Au INVENTOR.

BY @qz flwu United States Patent C) PRESSURE CONTROLLED GAS LIFT VALVEThomas E. Bryan, Fort Worth, Tex.

Application February 18, 1950, Serial No. 145,039

9 Claims. (Cl. 103-433) This invention relates to new and usefulimprovements in oil well flowing devices and, in part, is a modificationand improvement in the device shown and described in my co-pendingapplication, Serial No. 83,536, now abandoned, and it has particularreference to the art of raising oil flowed into the well tubing, underformation pressures, by artificial gas or air pressures introduced fromthe earths surface, and its principal object resides in the provision ofapparatus moving the oil upwardly in the tubing in time cycles, or atpredetermined intervals, in accordance with the productivity of thewell, and without imposing unnatural gas pressures upon the producingformations to impair their productivity by irretrievably displacing thepetroleum products.

An object of the invention resides in the provision of a valve structureembodying a mechanism which is adapted to be installed in the tubing ofa well at predetermined elevations or stages, the first of which shouldbe arranged near the bottom of the well, as the tubing is installedtherein, and others at spacings which are determined by the depth of theparticular well and the productive capabilities thereof, it beingdesirable to establish the valves along the fluid column at spacingsdesigned to lift the fluid with the minimum of applied pressures andwith a view to increasing such pressures progressively downward as theoil column is raised to the surface and the load is lessened.

Other flowing devices have been designed to accomplish the flowing ofoil from Wells, including that described in my co-pending application,Serial No. 66,605, now Patent No. 2,681,014. Some of these devices operating in some manner controlled by a pressure-controlled bellowsstructure, and incorporating a method of flow wherein greater pressuresare employed to accomplish the lift, or flowing operation, at or nearthe surfaceand successively decreasing the pressure to cause the devicesto operate as greater flowing depths are uncovered in the well. Thismethod of flowing oil has obvious disadvantages in that, at each cycleof operation from devices located lower in the well, less fluid can belifted to the surface resulting in waste of gas in proportion to thequantity of fluid lifted during each cycle. Another disadvantage in suchmethods of operation is obvious in that an attempt is made to utilizegas at lower pressures to accomplish a greater lift, where it is obviousthat more power is required to raise fluid from a single injection pointover a greater distance. A third objectionable result obtains inattempting to utilize gas at lesser pressures, wherein the energycontained in the gas is in proportion to its pressure, according toscientific authority, to accomplish the necessary lift and is contraryto natural laws controlling the energy factor of gas under pressure.

It is an object of the invention, therefore, to supply apparatus capableof operation in accordance with said natural laws, and each of saidvalves operating as a single injection point without assistance from anyother valve device spaced in the Well and to introduce gas at each valveat a pressure in proportion to the operation involved, wherein itbecomes greater as each lower valve is uncovered in the casing, andafter all the well fluid has been expelled from the casing, the lowestvalve in operation will be loaded to operate at a pressure conforming tothe increased depth, including the factor of friction developed by theflow, and permit the lifting of the greatest quantity of fluid up thetubing at each cycle.

Another object of the invention is that of providing an especiallydesigned fitting adapted to be connected into the tubing string at therequired spacings to support the valve mechanisms and have means thereonby which the valves can be removably attached exteriorly thereof andhave communication therethrough with the interior of the 5 tubing, thesupporting means being capable of rigidly securing the valve mechanismsin the tubing string in a manner calculated to minimize the hazards ofvibrations, and in operating the tubing into and out of the well.

A still further object of the invention is that of providing a pressurechamber for applied gas pressures exteriorly of the tubing in the casingby installing a packer about the tubing near the lower end thereof andexpelling or displacing the oil in the casing into the tubing throughthe lowermost valves and compressing air or gases into the pressurechamber by suitable apparatus, controlling such pressures, andmaintaining definite time cycles for introduction thereof, by pressureregulators and time control mechanisms which do not form a part of thisinvention.

Another object of the invention resides in the specific valve structuredescribed herein to accomplish these beneficial results whereby thecontrolling medium combination of bellows, pressure chamber and valveelements provided, permit a first opening operation of the valve so thatgas under pressure may enter the tubing, when the gas in the casingapproximates the loaded pressure of the bellows chamber, then increasingthe pressure in the easing annulus, forcing the second closure elementof the valve into contact with its seat thereby stopping injection ofgas through any valve. A third function sought is to reduce the pressurein the casing annulus after first opening the valve and permit thecasing pressure to fall by dissipation through the valve and to causethe valve to return to its first closedposition held there by the pressure in the bellows chamber. The next function sought is the provisionof successively increasing the loading pressure of each bellows chamberwhereby it requires a greater pressure in the casing to first open eachvalve to admit gas to the tubing and then still a greater pressure tocause the second valve closure element to stop passage of gastherethrough, and repeating the process successively downwardly to thelowermost valve, increasing the pressures as the greaterlift isencountered.

It is yet another object of the invention to provide a system of valves,located at predetermined elevations in the well, which can be adjustedor set to function at different applied pressures, each having apressure chamber capable of being loaded to a specified pressure andhaving a yieldable bellows element therein amenable to such pressure tomaintain one of the closure elements of the assembly against its seat toexclude the applied pressures from the pressure chamber in the wellcasing until such latter pressures reach a predetermined force, or aforce suflicient to be elfective against the closure element, and itsimpelling force, to move the element from its seat and open the passageinto the tubing, and then to close the same either by reducing thepressures to the original amount or by increasing the pressures.

Broadly the invention contemplates the provision of a device forselectively flowing fluid from a deep well in accordance with acceptedcorrect theories of accomplishing the highest efliciency and extractionof all the energy possible from gas under pressure and expending it into a column of fluid, and lifting the fluid in greater columns as lowerlevels are encountered in the well, thus resulting in the conservationof gas.

While the foregoing objects are paramount, other and lesser objects willbecome manifest as the description proceeds, taken in connection withthe appended drawings wherein:

Figure 1 is a longitudinal cross-sectional view of the valve structure,showing the supporting fitting fragmentarily, and illustrating thepressure chamber and bellows closure actuating element.

Figure 2 is a plan view of the valve assembly, the supporting fittingbeing fragmentarily shown.

Figure 3 is a transverse sectional view, on lines 3-3 of Figure l, andalso illustrating the supporting fitting fragmentarily.

Figure 4 illustrates, in elevation, the closure elements,

portions being shown in cross-section and fragmentarily,

and

. -.Figure is an inverted plan view of the valve assembly,

cycle control device at the earth s surface.

Figure 7 is a fragmentary view of the assembly shown in Figure 1 at thetop of the bellows member 66.

,Accordingly, the apparatus employed in the invention comprises,primarily, a valve assembly which is especially adapted for installationin specially designed fittings 10 arranged at predetermined elevationsalong the tubing 11 in the casing 12, as shown in Figure 6, a packer 13being installed about the tubing 11 near the bottom thereof to isolatethe annular space 14 within the casing 12 about the tubing 11, only atail pipe 15 extending below the packer 13into the production area 16 inthe well bore.

The casing 12 is closed at the top by a head 17 from which are extendedconduits 18 and 19 through which oil is conveyed to storage. Valves 20and 21 are respectively arranged in the conduits 18 and 19.

Each of the fittings 10 are cylindrical in form and have threadedportions 22 on each end adapting the devices to be connected by collars23 into the tubing 11. On one side of the fitting 10 is formed anintegral lug 24 near its lower end for supporting the valve assemblywhich will be presently described. A set screw 25 is threaded throughthe lug 24, in parallel axial alignment with the fitting 10 and has alock nut 26 thereon, as apparent in Figure 1.

Spaced above the lug 24 is an integral collar 27, also having its axisparallel to that of the fitting 10, and is interiorly threaded toreceive the exteriorly threaded portion 28 of a fitting 29 forming apart of the cylindrical housing for the valve assembly. An annulargroove 30 is formed within the collar 27 and intersects a port 31 in thewall of the fitting 10 within the collar 27, as shown in Figure 1.

The valve assembly is encased in a housing which consists of a bodyportion 32 upon the upper end of which the fitting 29 is threaded, thelower end being closed by a flanged nipple 33 secured into the lower endthereof, the nipple 33 being formed with a depending portion 34 havinginterior and exterior threads, a cap 35 being threaded thereon, as shownin Figure l. A recess 36 is formed in the bottom surface of the cap 35to receive the upper end of the set screw 25 by which the assembly issecured.

The member 29 has a reduced portion 37 on its upper end, above thethreaded portion 28, which extends through the collar 27 and projectsupwardly thereabove, its upper end being exteriorly threaded for theattachment of a cap 38 having a plurality of ports 39 therein. Themember 29 has a plurality of ports 40 which also open the port 31.Immediately above the ports 40, internally of the portion 37 of themember 29, is formed a pair of opposingly arranged seats 41 and 42having a passage 43 therethrough connecting at each end with chambers 44and 45 above and below the seats 41 and 42, respectively.

The seats 41 and 42 are engageable by closure members 46 and 47,respectively, coupled by a stem 48, as shown in Figures 1 and 4. Thestem 48 has a reduced portion 49 at its upper end defining a shoulder 50at the base of the reduced portion 49 and a threaded portion 51 on theupper end of the reduced portion. A circumferential groove 52 is formedin the portion 49 in which is arranged a packing ring 53, the uppermember 46 being arranged upon the portion 49, about the ring 53 andagainst the shoulder 50. Nuts 54 and 55 are threaded upon the portion 51to secure the upper closure member 46, as illustrated particularly inFigure 4.

The lower closure element 47 is integral with the stem 48 and has athreaded bore 56 by which it is attached to the threaded spindle 57formed on the upper end of a second stem 58 which will be presentlydescribed. The stem 48 is arranged through the passage 43 between theseats 41 and 42, as shown in Figure 1, retaining the closure members 46and 47 in proper position to engage the seats 41 and 42.

Below the lower closure 47 is a washer 59 which is arranged about thespindle 57 on the stem 58 and rests of the valve, and SllOWll'lg thepressure regulator and time into the groove 30 and consequentlycommunicates with 55 upon the shoulder 60 defined at the base of thespindle 57.

The closure member 47* is threaded against the washer 59. A groove 61 isformed about the stem 58 below the shoulder 60 and a packing ring 62 isarranged'therein, the function of which will presently become apparent.

In Figure l is shown a structure in which a sleeve 63 is pressed intothe fitting 29 above the upper end of the housing member 32 andsurrounds the stem 58, its internal diameter being sufficiently greaterthan the diameter of the stem 58 to provide an annular passage 64therearound capable of being closed by the packing ring 62 on the stem58 when the upper closure element 46 engages the seat 41. In theposition of the elements shown in Figure 1 the lower end of the stem 58extends into the bellows member 66 and is attached thereto at its lowerend, the passage 64 continues internally of the bellows 66 surroundingthe member'58 and affords fluid communication with the interior of thebellows. The upper end of the member 66 ends in a ring 65 forming anintegral part thereof, and this member is securely welded orsilversoldered to the interior upper end of the member 32 therebypreventing communication between the chamber 66 and the fitting 29through the passage 64. At the lower end of the member 66 a cap 67 isattached thereto forming a guide to maintain the bellows 66 and the stem58 secured therein in vertical alignment to enable the member 6766 and58 to move freely longitudinally in the chamber 66. Figure 4 shows amodification of this assembly with respect to attachment of the ring 65to the member 70, and clearly shows the passage 64, shown in Figure 1,in fluid communication with the interior of the ing member 32, adepending flange 71 affording means for attaching the upper end of thebellows member 66 to the sleeve 68, the bellows 66 being secured to theflange 71 by any suitable means, such as by silver solder. The lower endof the bellows 66 is attached to the stem 58 as by the arrangement shownin Figure 1.

The housing member 32 is loaded by air pressure through a loading valve72 threaded into the member 34 and enclosed by the cap 35, as shown inFigure l, the effect of the pressures within the member 32 being that ofacting upon the bellows member 66 to actuate the stem 58 to move thelower seat 47 against the seat 42 and close the passage 43 therethroughand the ports 40 and 31, shutting ofi passage of gas pressures from theannular chamber 14 in the casing 12 to the tubing 11 until the pressuresin the casing 12 reach a sufficient differential to move the closure 47from its seat 42.

It is desirable to space the valve assemblies along the tubing 11 in amanner calculated to suit the particular conditions, as the productivityof the well, or flow rate thereof, and the oil-gas-water ratio, thefirst consideration being that of determining, the common static fluidlevel under favorable conditions. The spacing of the valve assembliesare then spaced to meet the particular requirements.

For best results the bellows chamber 66' is loaded at pressures ranging,for example, from 500 pounds in the lowermost valve to 250 pounds in theuppermost valve, a differential of 50 pounds from one valve to anotherbeing a desirable practice. Thus, the greater applied pressures can beutilized at the bottom of the fluid column where such pressures canaccomplish the greater effect thereon although such an arrangement canobviously be reversed, if desirable, so that the uppermost valve cancarry the greater pressure load.

Automatic operation of the system is accomplished by setting the timecycle device 73, shown in Figure 6, to inject pressures into the casing12 at intervals determined by the time required to establish a selectedlevel for the fluid column in the tubing 11. The control assemblycomprises the time cycle element 73 which is afforded by a bypass tube74 connected between the conduit 75 and the element 73, a cut-off valve76 and reduction valves 77 and 78 being installed in the tube 74 wherebythe pressure in the casing 12 can be controlled to properly actuate thecycle device 73. As an example, if the casing pressure isapproximately-1000 pounds, the first reduction valve77 will reduce thepressure to approximately 250 pounds while the next valve 100 furtherreduces such pressure approximately 30 pounds at which the cycle device73 is actuated. Pressure in the cycle device is bled therefrom throughan outlet 79 on one side of the device.

The valve assemblies are operated, upon the occurrence of a suitableliquid level in the tubing, by gas pressures from the casing 12 enteringthrough the ports 39 in the cap 38 and through the passage 43 in theseat member 37 to bear against the lower closure 47 impelling thismember from its seat 42. The initial pressures admitted through thepassage 43 will pass downwardly about the member 47 and the Washer 59 toenter and extend the bellows 66 but such operation is instantaneous, andbefore excessive pressures enter the bellows 66, which might tend torupture the same, the member 59, with the sealing ring 62, Will haveclosed the passage 64 into the bellows 66 and the applied pressures arepassed directly into the tubing 11 through the ports 40 and 31,respectively, to lift the fluid column and as the casing pressures areincreased above the loaded pressures of the bellows chamber 66' thelatter will force the upper closure element 46 to its seat and shut oflthe pressures to the tubing. Each of the valves will function insuccession downwardly until the fluid in the casing has been expelledwhereupon all of the valves will be closed by the element 46 contactingits seat 41.

When the lowermost valve in the tubing string has been uncovered by thefluid column, gas in the casing is substantially reduced in pressure toequal the loaded pressure of the chamber 66 to enable the upper element46 to rise off its seat while the lower element 47 will be urged againstits seat, or to the original closed position, and the valve will be atrest until the fluid rises into the tubing to form another column.Thereafter the valve is operated at regular intervals to inject gas tothe tubing by action of the time cycle device 73 to raise the pressurein the casing to equal the loaded pressure of the valve thereby causingthe member 47 to again be forced from its seat to admit gas to thetubing.

This operation is maintained until all fluid is lifted to the surface,and when the time cycle device and regulator 79 are actuated to stopinjection of gas to the casing, the pressures therein will decrease bydissipation through the valve and the latter will close automaticallywhen the pressure falls to equal the loaded pressure of the valve, whichis the primary opening pressure of the valve, and this cycle may berepeated as often as the fluid flow of the well is required.

Manifestly, the apparatus herein shown and described is capable ofcertain changes and modifications, from time to time, by persons skilledin the art without departing from the spirit and intent of the inventionor the scope of the appended claims.

What is claimed is:

l. A flow valve structure for oil wells comprising; a valve body, saidbody having a flow passage therethrough terminating in an inlet port atone end and an outlet port at the other end, a valve member in said bodymovable from a first position wherein it interrupts said flow passageadjacent the outlet port through an intermediate position where thepassage is open to connect said ports to a third position wherein thevalve member interrupts the flow passage adjacent the inlet port, meansnormally biasing said valve member toward its said first position, meansresponsive to fluid pressure at the inlet port for urging said valvemember toward its said third position, fluid pressure responsive meansnormally connected with said outlet port responsive to fluid pressurefor urging said valve member toward its said third position, and meansresponsive to movement of said valve member from its first positiontoward its third position, and before the valve reaches its thirdposition, for interrupting the communication of said last mentionedfluid operable means with said outlet port.

2. A flow valve structure for oil wells comprising; a valve body, saidbody having a flow passage therethrough terminating in an inlet port atone end and an outlet port at the other end, a valve member in said bodymovabie from a first position wherein it interrupts said flow passageadjacent the outlet port through an intermediate position where thepassage is open to connect said ports to a third position wherein thevalve member interrupts the flow passage adjacent the inlet port, meansnormally biasing said valve member toward its said first position, meansresponsive to fluid pressure at the inlet port for urging said valvemember toward its said third position, fluid pressure responsive meansnormally connected with said outlet port responsive to fluid pressurefor urging said valve member toward its said third position, and meansresponsive to movement of said valve member from its first positiontoward its third position, and before the valve reaches its thirdposition, for interrupting the communication of said last mentionedfluid operable means with said outlet port, the said means interruptingcommunication between said outlet port and said fluid operable meansalso being operable to prevent the said communication during furthermovement of said valve member toward its said third position.

3. A flow valve structure for an oil well comprising; a valve bodyhaving a flow passage therethrough with an inlet port at one end and anoutlet port at the other end, a valve seat in said flow passage, a valvemember having seat engaging elements spaced thereon, one on each side ofsaid seat whereby said valve member has a first position where thepassage is closed adjacent the outlet port, an intermediate positionwhere the passage is open to connect said port, and a third positionwhere the passage is closed adjacent said inlet port, an expansiblebellows open at one end and closed at the other end, said expansiblebellows having one end connected to the body and its other end connectedwith said valve member and biasing said valve member toward its firstposition, said body being formed with a cavity surrounding said bellowswhereby the bellows divide the cavity into two chambers, passage meanscommunicating one of said chambers with said outlet port, means forsupplying a compressible fluid under pressure to the other of saidchambers and entrapping it therein, means responsive to fluid pressureat said inlet port for urging said valve member from its first positiontoward its third position, and means responsive to a predeterminedamount of travel of said valve member away from its first position forinterrupting said pas sage means.

4. A well flowing arrangement including a flow string, a series ofvalves carried by the flow string at different points therealong forcontrolling communication between the interior of the string at variouslevels and the space surrounding the said string, the space: surroundingthe said string being in communication with a source of gas underpressure, each said valve having a flow passage therethrough with oneend opening externally of said valve and the other end opening to theinterior of said string, a valve member in each said valve having oneposition where the flow passage therethrough is interrupted adjacent thestring, an intermediate position where the said passage is open, and athird position where the said flow passage is interrupted adjacent theend thereof opened externally of the valve, a bellows having its openend connected with the valve body and its closed end connected with saidvalve member, means for supplying a compressible fluid under pressure tothe side of said bellows opposite its connection with said valve memberand for entrapping the fluid therein to move said valve member towardits said first position, means responsive to fluid pressure in the spacesurrounding said string for moving said valve member toward its saidthird position, means communicating the other side of said bellows withthe interior of said string while the valve is in its said firstposition, and means for interrupting said communication in response to apredetermined amount of movement of said valve member away from its saidfirst position.

5. A well flowing arrangement as claimed in claim 4, with said valvesresponsive to increased pressures as said valves are located fartherdownwardly on the flow string.

6. A well flowing apparatus including a tubing having a well fluid inletand a port for admitting a pressure fluid, a valve including a housingattached to the said tubing for controlling the admission of thepressure fluid through the port into the tubing, said valve housinghaving a ported passage therethrough connected to said port forconducting the pressure fluid into the tubing, 21 valve stem operatingwithin the passage having dual seating surfaces controlling flow throughsaid passage, one of said surfaces being exposed to the pressure fluidand actuated thereby to move said stem to open the passage, the other ofsaid seating surfaces movable to close said passage upon a predeterminedmovement of said stem, a bellows in said housing surrounding a portionof said stem and attached thereto at one end and anchored to the housingat the opposite end, a pressure fluid confined within the -valvehousingand surrounding said bellows and urging said stern in a direction tooppose the pressure fluid, passage means formed between the stem and theinterior of the said housing providing an open fluid communicationbetween the interior of the bellows with the tubing through the portwhen the passage through the valve is normally closed, and means on saidstem for closing the fluid communication between the interior of thebellows and the tubing when the said passage is open and excluding thepressure from the interior of the bellows.

7. A flow valve structure for oil wells including a body adapted to beconnected to a port in the well tubing and lowered therewith in the wellcasing and having a passage therethrough connected to the port forestablishing communication between the tubing and the casing, a doublevalve seat within the passage, a movable valve stem operating within thepassage, and through said double seat, dual valves on said stem andspaced apart thereon, one on either side of said seat for controllingflow through said passage, a flexible bellows positioned within saidbody and sealed thereto at one end, said stern extending into saidbellows and attached thereto at its lower end, means to confine apressure fluid within said section of said body and surrounding saidbellows whereby said bellows isv compressed urging said stem in adirection to close said passage by one of said dual valves, passagemeans formed between said stem and the interior of the body providingopen communication between the interior of the bellows and the interiorof the tubing through the port when the passage through the valve isclosed and means fixed on the stem to close the communication betweenthe interior of the bellows and the casing when the passage is opened.

8. A flow valve structure for oil wells in combination with the tubingand easing of the well including a body adapted to be connected intosaid tubing and lowered therewith in the well casing, a flow passagethrough said valve body having fluid communication with said casing atone end and communicating with the said tubing adjacent its other end, adouble valve seat within said passage, a movable valve stem extendingthrough said seat having spaced valve closure elements thereon, one oneither side of said seat, said stern and valve elements being movable toclose said passage in either direction upon the application of apredetermined pressure at either end, a bellows connected to said valvebody, one end of said stem extending into said bellows and attachedthereto, means to confine a pressure fluid within said valve bodysurrounding the bellows whereby said bellows and stem are urged in adirection to normally maintain said passage closed, means formed betweenthe stem and the interior of the tubular.v body providing an open fluidcommunication between the interior of the bellows and the flow passagebelow the valve seat hence to the tubing when the passage is closed bysaid valve closure elements and means onsaid stemtor closing said lastmentioned communication to the interior of said bellows when the passageis opened.

9. A flow valve structure for ,oil wells adapted to be connected to thewell tubing and lowered therewith into the well casing, said valvestructure having a jointed sectional tubular body, a passage through oneof said sections open to the casing at one end and communicating withthe tubing at the other, valve closure elements in said passage forcontrolling flow therethrough acted upon by pressures in the casing,spaced valve seats in the passage engageable by said valve closureelements, a movable valve stem carrying said valve closure elementsspaced thereon, a bellows having its open end connected to anothersection of said body and extending therein,.a portion of said valveextending through said open end into said bellows and connected theretoat the closed end of the bellows, means to confine a pressure fluid insaid tubular body surrounding said bellows urging said bellows and saidvalve in a direction to close said passage, means formed between thestemand the interior of the tubular body providing an open fluidcommunication between the interior of the bellows and the flow passagebelow the valve seats hence to the tubing when the passage is closed bysaid valve closure elements, and means on said stem for closing saidlast mentioned communication to the interior of said bellows when thepassage is opened.

References Cited in the file of this patent UNITED STATES PATENTS2,137,441 Bryan Nov. 22, 1938 2,236,864 Worthington Apr. 1, 19412,241,656 Crickmer May 13, 1941 2,339,487 King Jan. 18, 1944 2,465,060Carlisle Mar. 22, 1949 2,519,242 Garrett Aug. 15, 1950

